Combination square and bevel



f 1,621192 March 5, 1927. I R. A DYKE f COMBINATION SQUARE AND BEVEL Filed June v, 1924 2 sheets-sheet 1 March 15 1927.

R. A. DYKE COMBINATION SQUARE AND BEvEL Filed June 7, 1924 2 Sheets-Sheet 2 Patented Mar. l5, 1927.

'mios ABIJAi-r nY'irE, 'or MYRTLE POINT, OREGON.

*Application 'ld June 7,1924. Seralr'iNo, '718,621;

This invention relates to mechanics Vsquares,'especially to carpenters squares and particularly to' theA latter With attachments 'flor facilitating the laying outof angles and vfor solving mathematical problems relating thereto. y

The objectsof my invention are toPp'rovide a 'tool which willl serve" as asquare and pro- `videlr for laying outand scribing of any desired angle on timbers and other material Vin connection 7With carpentering or 'similar "Work and i'v'hic'h' willautomatically indicate vthe length of 'the'hypotenuse of"y any right angle' triangle, the basis of all ordinary roof- "ingfprobleins inf 'the'joining of the timbers.

l/vlhile'my invention' is not limited to" the "solving of roof 'frame nroblemsfsin'ce'the4V ins'trument f mayr be] arbitrarily graduated' to suit any 'particular class of "Work, its" application to thef framing of 'roofs appears to be y'the most useful, 'and therefore' the graduations and"examples given hereinafter" refer tdth'is' i'isage. i y

BrieflyA stated 'my invention comprises 'a right angle'triangle'with atelescopic hypotenuse pivotally secured'to one side of the triangle and'slidablealong 'the Votherfthe vsides and telescopic li'ypotei'i'use*bearing cooperating or `related "series of graduations Vl'iav'ing 'certain Telationto'* the" problems' to befs'olved. l

The instrument may be of' any' size and 'the graduation's-y proportionately spaced 'to suit, but a practicalrsiyze for Qarpentering is about a foot in greatestlength,` though if made tWo feet long the graduations are further spaced and may be more easily read. i Y

In the drawings, Figure 1 shows one side of my instrument, and Figure 2 the other side, .While Figure 3 is an edge view of the telescopic hypotenuse or fence as such a hypotenuse is called when applied to a car-A penters square.

In further detail the instrument comprises a 90o square having a blade B, a tongue T and a fence F.

rl`he fence is telescopic, and bifurcated at both ends to straddle both the tongue and the blade, and it is pivotally connected to the blade at a point A by a hinge the pivot of which is coincident with the upper edge of the blade in such a manner that the fence can fold down parallel to the blade as shown in dotted position in Figure 1.

The tongue is slotted at S and the free end of the fence is adjustable on the tongue Withthe same edge 'of ""s'ec'ts the pivot'A.

endto bind upon the tongue.

through eiigagementlwith a; pin' P extending throii-ghthe slot and `carried byla sliding block Z). The centerof the-pin is coincident the felice which inter- The'f'ence telescopes by having a thinner "portion which bears the lgraduations slide V'Withinfthethiclrer lower blade straddling 'portion assh'own. jThe tonguestra'ddling portion iisi-provided with'V a elampin'gscrew `3`a'nd'-'1a"nut -CWher'eby the 'fencem'ayf'lole V'cian'ip'ed to any adjusted position ,along the tongue by turning the nut c up'on the" screw '3 "which causes-'the sides of the -bi'fi'ircated `Several 'rows of graduations areshovvn 'along both sides vof thef tongue Land fence.

These graduations" arefor :the solving of roof frame" construction yproblems and vare 'based on the common method 'of using' 12 rin'ches,^1(' inches' and 13'n inches onv tlievbla'vde of a carpenters steel square as respectively representing the run' of common rafters," hip rafters and VOctagon' "hip rafters and Vmeasuring the] length from these points across the corner oftheisquareito the proportionate rise of the roof 'on the: tongue' of" the vsquare to 'obtain thel unit length for each? footfof span 'ofthe 'roof' for common,`"hip or octagon'fhip rafters respectively andalso-to' determine l theirV plumb and `bevel. cuts'in connection 'ivitli" the 4frame constructionv ofa '450' pitch room-Y My instrument, While lusing the same principle, lautomatically' registers on' the'l several scales G on the movable telescopic fence the unit lengths referred to above, and also in addition scales the difference in length of jack rafters, abutting hip or valley rafters at 12, 16 or 24 inch spacing. Y

By pivotingl and centering the fence at A and P on its Working edge as described, it allows the base of the triangle to remain permanently at a predetermined length since the moving center P While traveling along the slot in ZF is in a line perpendicular to its starting point, and thus indicates at any position of fence F with the aid of theV proportionate scales on T and F the relative lengths of the three sides of a right angle triangle.

On the instrument.y not drawn to scale the divisions (12) on T comprise a substantially 'one-half scale standing perpendicular to the base and distant from center A 12 inches of the same scale. Moving F to inas shown in Figure l, it is in position for marking a miter of 450 or the plumb and bevel cuts of rafters for a square pitched roof. i Y

At the same time on a scale exposed on the extendedfence at the'point Where it pulls out Will be found the extended length between centers A, P on F, orthe length of a common rafter per foot of run. In other columns G will be'rfound indicated the di'erence in lengthA of jack rafters spaced 16 or 24 apart.

Scale 17 on Vtongue T represents a distance of seventeen inches from center A. Moving the fence F to 12in column 17 the blade gives the bevel cut of hip rafter and the tongue theplumb cut. In the column nearest the inner side on F the length ofhip rafters for one foot of run isv automaticallyregisltered by the mark of the scale nearest to the inner edge of the blade straddling portion of the fence F.

In the case of common'and hip rafters it remains only to multiply the unit length registered on the scale' by the run of roof,

s fi. e. half the Width of building, to find the total length of rafters. y

In the column on T for hip side cut on tongue this is-the bevel required to fit a hip rafter against the ridge board, or opposite hip rafter, and the scale indicates one inch rise per-foot between each division.

In the column for jack rafters side cut on blade, the bevel formed by F and BV fits the jack rafters sideways against hip orY valley rafters `(the ordinaryplumb cut of common rafters isl used for the up and down cut). The side eutinvariably so called, is marked on the edge of the rafter.

On the reverse side of the instrument, Figure 2 there is a column for common rafter rise, giving plumb and bevel cuts, also the length on fence, and in other columns giving the lengthsv of octagon hip t rafters, and the difference in length of octa-V shown that scales different from those shovvn` may be provided, and it should be noted that the fence being thicker than the blade and tongue may be placed against the timber from either side in scribing. y

I am 'aware of the use of a graduated fence in connection with the common steel square for similar usage, but I do not know of such a fence being permanently pivoted to a square providing a definite base and being` made telescopic with several columns of proportionate figures thereon bearing a relation to proportionate scales along the tongue. f

I claim: y

1. A combination square having two legs forming a right angle, an eXtendible fence pivoted at one end to the free end of the first leg and with the other end engaging the second leg and being slidable therealong, there being a lineof graduations along the sec-0nd leg` having proportionate relation to Vroof timber rises, the `distance from said line of graduations to the pivotal point taken along the first leg having the same proportionate relation to the roof timber runs, and the eXtendible fence having graduations registering in similar terms quantities depending upon the angular relation of the fence to the legs.

2. A combination square having tWo legs forming a right angle and one of said legs having a slot, an exten-dible fence pivotallyV connected at one end to the free end of the unslotted leg, a block slidable in the slot of the other leg and having means bearing upon the free end portion of said fence.

lunos ABIJAH DYKE. 

